This invention relates, in particular, to a fuel metering and injection system for mixture compressing, externally ignited internal combustion engines. The system includes a fuel line and a metering valve in the fuel line, the valve having a movable valve member which, especially when the movable valve member is embodied as a slide-valve piston, meters out to the air quantity streaming through a suction tube a quantity of fuel in a desired proportion, and where the movable valve member (slide-valve piston) can be actuated by a fluid of changeable pressure to influence the metering process. It is the purpose of such fuel metering and injection systems to create automatically a favorable fuel-air mixture for an internal combustion engine, in order to burn the fuel as completely as possible and, therefore, to avoid or to reduce greatly the formation of toxic exhaust gases while maintaining the highest possible performance or the lowest possible fuel consumption of the internal combustion engine. For this purpose, the desired ratio between air quantity and fuel quantity must be changeable in dependence on engine parameters, such as rpm, load, temperature and exhaust gas composition. Such an adjustment should be possible by the simplest means, i.e. by a simple intercession in the control loop mechanism of the fuel injection system.
In a known fuel injection system of the above-described kind, the slide-valve piston is actuated by a mechanical air measuring element via a lever against a nominally constant return force (pressure fluid). This known fuel injection system is limited with respect to the intercession in the control loop mechanism.